A Journey Through the Flames of War in the Republican Era

With the help of information sent back by Falkenhausen and Newegel, the German Communications Authority quickly made technical improvements to the Enigma machine.

In order to avoid arousing suspicion from French and Polish intelligence agencies, the Germans deliberately made these improvements appear as normal, gradual performance updates and enhancements.

The Germans took several measures: First, they readjusted the wiring method inside the scrambling rotor.

二、把转子的数量从3个增加到5个，使用的时候从5个转子中随机选择3个安装到密码机上。这样一来，3个转子的排列组合数量就从6种变成了60种。

More importantly, the "letter ring characteristic value" comparison table that the Poles had painstakingly compiled and recorded over a great deal of time was completely rendered useless. Recreating a dictionary in the original way would cost ten times as much.

Third, the number of letter connections on the power strip was increased from 6 pairs to 10 pairs, which greatly increased the key space, by several times.

This is a fatal blow to Polish experts, whose computing power has reached its limit. They used to use six identical "bomb machines" to test six different combinations of rotors, but now they need 60 machines to achieve the same efficiency.

The cost of manufacturing such a new "bomb machine" is several times that of the original one, and 60 machines would cost hundreds of times more. This is a huge financial hole, and their budget, which they have borrowed to make ends meet, is already stretched thin.

Hitler, along with high-ranking German figures such as Blomberg and Göring, as well as Falkenhausen and Newegel, who maintained close communication with experts in Nanjing and China, finally breathed a sigh of relief, thinking that even if they could not rest easy this time, at least they could make the other side helpless for a short period of time.

However, Song Hongfei quickly dealt Falkenhausen and Neviger a blow by demonstrating to them a method for cracking the improved Enigma machine.

The Germans were utterly shocked. These improvements were kept strictly confidential, inaccessible to unauthorized personnel, and completely unknown to the outside world. They hadn't disclosed the new wiring method inside the scrambling rotor to the Chinese side; how did Song Hongfei know?

Song Hongfei casually stated, "My paper includes a method for deducing the internal wiring state of the rotor from the ciphertext and key. The mathematical principle behind this is the permutation matrix. By leveraging the powerful computing capabilities of computers, we can solve this matrix equation, which is feasible within a limited timeframe."

Falkenhausen and Neviger exchanged bewildered glances, cold sweat pouring down their backs. This meant that the improvements to the cipher machine had been rendered ineffective before they could be widely adopted; their code was virtually transparent to skilled codebreakers.

Song Hongfei made it sound simple, but in reality, he also took full advantage of the "eye of God".

Having traveled from the future, he knew about the improvements Germany made to the Enigma machine between 1938 and 1940. Although his appearance added variables to the course of history, the result remained the same; the German improvements were simply brought forward by a year or two.

However, Song Hongfei could not determine whether, given these changes, the Poles and Allied experts after the outbreak of World War II would still be able to crack the German code machines as they had in history.

Although the outcome of a war depends on overall strength, intelligence warfare is not the primary factor, but it is still an important one that cannot be ignored. He had previously deduced that the closer the fighting became in the European war, the less it would affect the Far East. On the contrary, it would be more advantageous for China to sit back and watch the two sides fight, which was the optimal solution for China's strategic maneuvering.

In the blink of an eye, a thought suddenly popped into my head: Could this incident be the reason why the Germans launched their blitzkrieg by attacking Poland first, which led to the outbreak of World War II?

It was a sudden, startling realization, enough to stir up a thousand waves in his heart.

However, Song Hongfei did not think there was anything wrong with his actions. When it comes to national interests, there is no such thing as morality or sentiment. Now the Japanese are making trouble in North China, and the situation is extremely urgent. China urgently needs to strengthen itself. In the face of internal and external troubles and turmoil, any action taken in the name of the country is justifiable and justifiable.

Furthermore, at that time, relations between Poland and China were not friendly.

Caught between the two superpowers, Germany and the Soviet Union, Poland was always more wary of the Soviet Union than of Germany. As early as the Paris Peace Conference after World War I, Poland's diplomatic strategy was to try its best to sacrifice China to win over Japan, intending to support Japan's aggression and expansion in the Far East in order to contain its arch-enemy, the Soviet Union, a strategy that was more blatant than that of the major powers.

From then on, Poland and Japan, each with their own ulterior motives, quickly reached an agreement and colluded on issues concerning China, seriously damaging China's interests.

Song Hongfei clearly remembers that later materials showed that Poland and Japan cooperated in intelligence at the time, with Poland passing on its expertise in codebreaking to Japan, which enabled the Japanese army to make rapid progress in codebreaking technology. Around the time of the September 18 Incident, the Japanese army was able to decipher a large number of telegrams between Zhang Xueliang, the Northeast Army, and Nanjing, thanks in large part to the Polish advisors to the Kwantung Army.

When the League of Nations voted on sanctions against Japan to uphold peace and justice, Poland openly opposed it, blatantly supporting Japan. After the establishment of the puppet state of Manchukuo, Poland engaged in diplomatic activities with it, seriously infringing upon China's sovereignty. The top leadership of the Nationalist government was extremely angry about Poland's actions.

Repaying evil with kindness has never been Song Hongfei's style. If you did the first thing, don't blame me for doing the fifteenth; you only have yourself to blame. A friend of an enemy may not be an enemy, but he will never be a friend either. Repay evil with justice and kindness with kindness; it is impolite not to reciprocate.

Shocked, the Germans took further measures to strengthen the security of the cipher machine:

First, the rotor was modified so that the letter ring on the outside of the rotor core can rotate around the rotor core to set different positions.

Second, the initial position of the rotor in the daily key is also left to the sender to choose.

In this way, the daily key in the universal codebook no longer includes the initial position of the rotor, and the first six letters of each coded message are encrypted using a different key. The major flaw of "using the same universal key for encryption on a large scale" is thus remedied.

However, to the Germans' astonishment, Song Hongfei then demonstrated another effective method of cracking the code. The German communications and cryptography experts simply couldn't believe that the secret they had painstakingly devised had been so easily cracked so quickly.

Song Hongfei said, "Double encryption is a fatal flaw. No matter how it is modified, it remains the same. As long as this point is not eliminated, there is a way to crack it."

German experts practically regard Song Hongfei as a genius, and can only marvel at the boundless wisdom of humankind.

This cracking method only became completely ineffective after the Germans stipulated that the information key only needed to be entered once—meaning that the Polish cracking method could no longer be used.

For a moment, the Germans were practically ecstatic.

However, the fact that "a single letter encrypted with a letter will never be itself"—a flaw that seems insignificant—cannot be remedied through improvement, and the Germans never realized it was a flaw. It wasn't until they saw Song Hongfei's materials that they were struck dumb, completely stunned.

Due to the structural design principles of the Enigma cipher machine's reflector, the only way to remedy this vulnerability was to completely redesign the cipher machine.

German experts carefully studied Song Hongfei's solution to this flaw. After meticulous deduction, they found that the solution was theoretically possible, but impossible to implement manually.

Song Hongfei calmly said, "The methods for cracking cipher machines have exceeded the limits of human capabilities. However, just because humans cannot do something does not mean that computers cannot do it either. Enigma is a cipher monster created by machines, and naturally, machines can also defeat it."

What Song Hongfei described was the solution sought by British expert Alan Turing during World War II. However, given the current situation, Turing's work will likely be nipped in the bud before it even comes to fruition. Of course, this enormous secret cannot be revealed to outsiders.

The German experts were speechless, but already completely convinced. They were also utterly clueless about computers; at that time, Germany had not developed a truly modern computer, nor did any other part of Europe—only the United States and China possessed one.

The Germans naturally understood that although it was impossible for humans to crack, it also showed that Enigma was not a perfect cryptographic system, and its psychological impact on them was undeniable.

Hitler could no longer remain calm. "This Song Hongfei—" He couldn't help but feel a sense of profound mystery about him.

"Their computers are so incredibly powerful?" Hitler seemed to be deep in thought.

After pondering for a long time, he sighed, revealing a bitter and helpless expression, and muttered to himself, "In this respect, they are the teachers, and they are indeed ahead of us."

No matter how much Hitler boasted about the nobility and superiority of the Aryan race, he had to put aside his arrogant attitude of looking down on the East.

After fully recognizing the astonishing power of modern technology, the German think tank was amazed and had already suggested to him that they should humbly learn from China about modern computer technology. He was deeply moved and immediately approved the suggestion without hesitation.